The present invention is directed to neuroprotective (antiischemic and excitory aminoacid receptor blocking) 2-piperidino-1-alkanol derivatives defined by the formulas (I), (II) and (III) below; pharmaceutically acceptable salts thereof; a method of using these compounds in the treatment of stroke or CNS degenerative diseases such as Alzheimer's disease, Huntington's disease and Parkinson's disease; and to certain intermediates therefor.
Ifenprodil is a racemic, so-called dl-erythro compound having the relative stereochemical formula ##STR2## which is marketed as a hypotensive agent, a utility shared by a number of close analogs; Carron et al., U.S. Pat. No. 3,509,164; Carron et al., Drug Res., v. 21, pp. 1992-1999 (1971). More recently, ifenprodil has been shown to possess antiischemic and excitory aminoacid receptor blocking activity; Gotti et al., J. Pharm. Exp. Therap., v. 247, pp. 1211-21 (1988); Carter et al., loc. cit., pp. 1222-32 (1988). See also French Patent 2546166. A goal, substantially met by the present invention, has been to find compounds possessing such neuroprotective effect in good measure, while at the same time having lowered or no significant hypotensive effect.
Certain structurally related 1-phenyl-3-(4-aryl-4-acyloxypiperidino)-1-proponols have also been reported to be useful as analgesics, U.S. Pat. No. 3,294,804; and 1-[4-(amino- and hydroxy-alkyl)phenyl]-2-(4-hydroxy-4-tolylpiperazino)-1-alkanols and alkanones have been reported to possess analgesic, antihypertensive, psychotropic or antiinflammatory activity, Japanese Kokai 53-02,474 (CA 89:43498y; Derwent Abs. 14858A) and 53-59,675 (CA 89:146938w; Derwent Abs. 48671A).